feat(lambda-event-sources): dead letter queue and filter policy for sns event source

packages/@aws-cdk/aws-lambda-event-sources/README.md

@@ -113,8 +113,12 @@ import * as sns from '@aws-cdk/aws-sns';
 import { SnsEventSource } from '@aws-cdk/aws-lambda-event-sources';
 
 const topic = new sns.Topic(...);
+const deadLetterQueue = new sqs.Queue(this, 'deadLetterQueue');
 
-lambda.addEventSource(new SnsEventSource(topic));
+lambda.addEventSource(new SnsEventSource(topic, {
+  filterPolicy: { ... },
+  deadLetterQueue: deadLetterQueue
+}));
 ```
 
 When a user calls the SNS Publish API on a topic that your Lambda function is

packages/@aws-cdk/aws-lambda-event-sources/lib/sns.ts

@@ -2,14 +2,23 @@ import * as lambda from '@aws-cdk/aws-lambda';
 import * as sns from '@aws-cdk/aws-sns';
 import * as subs from '@aws-cdk/aws-sns-subscriptions';
 
+/**
+ * Properties forwarded to the Lambda Subscription.
+ */
+export interface SnsEventSourceProps extends subs.LambdaSubscriptionProps {
+}
+
 /**
  * Use an Amazon SNS topic as an event source for AWS Lambda.
  */
 export class SnsEventSource implements lambda.IEventSource {
-  constructor(readonly topic: sns.ITopic) {
+  private readonly props?: SnsEventSourceProps;
+
+  constructor(readonly topic: sns.ITopic, props?: SnsEventSourceProps) {
+    this.props = props;
   }
 
   public bind(target: lambda.IFunction) {
-    this.topic.addSubscription(new subs.LambdaSubscription(target));
+    this.topic.addSubscription(new subs.LambdaSubscription(target, this.props));
   }
 }

packages/@aws-cdk/aws-lambda-event-sources/test/test.sns.ts

@@ -1,5 +1,6 @@
 import { expect, haveResource } from '@aws-cdk/assert';
 import * as sns from '@aws-cdk/aws-sns';
+import * as sqs from '@aws-cdk/aws-sqs';
 import * as cdk from '@aws-cdk/core';
 import { Test } from 'nodeunit';
 import * as sources from '../lib';
@@ -47,4 +48,67 @@ export = {
 
     test.done();
   },
+
+  'props are passed to subscription'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const topic = new sns.Topic(stack, 'T');
+    const queue = new sqs.Queue(stack, 'Q');
+    const props: sources.SnsEventSourceProps = {
+      deadLetterQueue: queue,
+      filterPolicy: {
+        Field: sns.SubscriptionFilter.stringFilter({
+          whitelist: ['A', 'B'],
+        }),
+      },
+    };
+
+    // WHEN
+    fn.addEventSource(new sources.SnsEventSource(topic, props));
+
+    // THEN
+    expect(stack).to(haveResource('AWS::Lambda::Permission', {
+      'Action': 'lambda:InvokeFunction',
+      'FunctionName': {
+        'Fn::GetAtt': [
+          'Fn9270CBC0',
+          'Arn',
+        ],
+      },
+      'Principal': 'sns.amazonaws.com',
+      'SourceArn': {
+        'Ref': 'TD925BC7E',
+      },
+    }));
+
+    expect(stack).to(haveResource('AWS::SNS::Subscription', {
+      'Endpoint': {
+        'Fn::GetAtt': [
+          'Fn9270CBC0',
+          'Arn',
+        ],
+      },
+      'Protocol': 'lambda',
+      'TopicArn': {
+        'Ref': 'TD925BC7E',
+      },
+      'FilterPolicy': {
+        'Field': [
+          'A',
+          'B',
+        ],
+      },
+      'RedrivePolicy': {
+        'deadLetterTargetArn': {
+          'Fn::GetAtt': [
+            'Q63C6E3AB',
+            'Arn',
+          ],
+        },
+      },
+    }));
+
+    test.done();
+  },
 };